XXYY syndrome

a disorder in which a male is born with a double complement of the normal XY chromosome pair (46, XY). Skeletal deformities, genital anomalies leading to infertility, enlarged breasts, and eunuchoid abdominal and hip fat are among the physical traits. Learning disabilities, especially reading problems, are common, along with delayed development of motor skills. Also called 48,XXYY syndrome.

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Psychology term of the day

February 16th 2025

sun compass

the use of the sun as a directional stimulus in orientation and navigation. Because the sun appears to move across the sky during the day and has different trajectories in different seasons, a sun compass must be coupled with some form of time estimation. To head south at 9 a.m., one needs to keep the sun on the left, but at 3 p.m., one needs to keep the sun on the right. Studies of several species, ranging from bees to fish and birds, have demonstrated a time-compensated sun compass. For nocturnal species, there is evidence of a star compass.